The present invention relates generally to dockable appliances or devices, and more specifically, to apparatus comprising an appliance docking tray and dockable appliance employing three point contacts that does not require physical alignment of the appliance to provide connections for power and data transfer.
Portable electronic appliances such as digital cameras and Personal Digital Assistants are more useful when they can connect to PC""s, printers, TV""s, kiosks, or other larger xe2x80x9cfixedxe2x80x9d devices. This can be accomplished with cable interfaces, such as USB, FireWire, or RS232. It can also be done wirelessly with infrared, Bluetooth, or 802.11.
Many of these portable appliances use rechargeable batteries that require them to be connected to a charger as well. It is often the user""s routine to connect the portable appliance to the charger and to a PC whenever it is xe2x80x9chomexe2x80x9d. Some appliances have integrated cables that connect to both charger and PC through a single connector.
A more elegant and convenient solution is to provide a dock or cradle that is semi-permanently wired to the xe2x80x9cbasexe2x80x9d appliance. This dock also either contains, or is connected to, the battery charger. It is designed to conform to some physical feature(s) on the appliance in order to align their electrical connectors together as the user places the appliance in the dock.
The disadvantage of the dock concept is that it must be designed to accommodate the form factor of that particular portable device or appliance. It can only be used for other products if all of them were designed with the same alignment features. If these features are small and unobtrusive, then it is more difficult for the user to dock the appliance. If the alignment features conform to the appliance""s shape, then it imposes those design constraints on all of the appliances.
What is needed is a dock that will work with a broad variety of electronic appliances, requires no effort from the user to align when docking, and imposes few if any constraints on the product design of the appliance.
Accordingly, it is an objective of the present invention to provide for an improved appliance and docking tray that overcomes the limitations of conventional devices. It is another objective of the present invention to provide for an appliance having three point contacts and cooperative appliance docking tray that requires no physical alignment of the appliance to provide connections for power and data transfer.
To accomplish the above and other objectives, the present invention provides for apparatus comprising an appliance having three point contacts and an improved appliance docking tray or xe2x80x9cdockxe2x80x9d. The docking tray is used to connect the appliance to an external device, such as a computer, for example. The appliance has three point contacts that touch a coarse grid of contacts on the docking tray.
The dock is formed in the shape of a tray whose top surface comprises a coarse grid of metallic electrical contacts. The appliance is designed to have three point contacts or xe2x80x9cfeetxe2x80x9d on its bottom surface. When the appliance is placed anywhere on the top surface of the docking tray, the three metallic feet contact at least three different electrical contacts of the grid on the top surface of the tray.
The three electrical contacts are sufficient to provide power to the appliance, and to exchange or transfer data. The dock comprises means, such as a switch and processor, for example, that electronically switches or selects, from all the contacts in the grid, those contacts that are touched by the feet of the appliance. Thus the dock can switch the power, ground, and data signals to whichever contacts on the grid are touched by the corresponding three contacts of the appliance.
In order to identify the location of the feet of the appliance on the contacts of the grid, the dock scans the grid electrically. The appliance is identified, for example, by its electrical impedance. In other words, the position of the appliance is known when current flows between the two appropriate grid contacts. The data contact is found by scanning the grid as well. The dock sends a query message to each contact until it gets a response.